From endocrine to cardiac storm: ventricular fibrillation in a young patient with thyrotoxicosis and Brugada syndrome
Both, L., Wijk, J.P.H. van
Voorzitter(s): prof.dr. J.L.C.M. van Saase, Rotterdam & dr. J.W.J. van Esser, Breda
Locatie(s): Zaal 0.4
Categorie(ën):
Background: Graves disease is the most common cause of thyrotoxicosis. Thyroid storm is a rare but life-threatening complication of Graves disease. We present a case of a 19-year-old male who was hospitalized for ventricular fibrillation due to thyrotoxic storm
Case: A 19-year-old man was admitted to the emergency room due to an out-of-hospital cardiac arrest. Ventricular fibrillation was noted on electrocardiographic monitoring and reverted to sinus rhythm after repeated defibrillation and basic life support. He had a history of Graves’ hyperthyroidism for 3 years and was treated with radioactive iodine 4 months before admission. Block-and-replacement therapy (strumazol 30 mg and levothyroxine 100 mcg) resulting in euthyroidism was given until 2 weeks before admission when it was stopped on our advice.. On admission, laboratory examinations revealed elevated free thyroxine (62 pmol/L, normal 10-24 pmol/L) and suppressed thyroid-stimulating hormone (< 0,01 mIU/L, normal 0,3-4,5 mIU/L). Thyroid storm due to recurrent Graves disease, presenting with ventricular fibrillation was diagnosed. He was treated with propylthiouracil 200 mg every 4 hours, propranolol 40 mg every 8 hours, hydrocortisone 100 mg IV every 6 hours, acetaminophen 500 mg every 6 hours and, after propylthiouracil was given, Lugol solution 20 drops every 8 hours. Free thyroxine levels normalized within a few days.
Initial post resuscitation echocardiography revealed generalized ventricular failure which complete recovered after reaching euthyroidism. Coronary angiography revealed no abnormalities. Cardiac MRI suggested left ventricular hypertrophy, normal RV and no signs of fibrosis. Post resuscitation electrocardiography showed an incomplete right bundle branch block and upsloping ST-segment in V2 and V3. Family history was negative for sudden death or cardiac arrhythmias. With Ajmaline the right precordial leads changed to a type 2 Brugada repolarization pattern. Brugada syndrome is a hereditary arrhythmia characterized by specific electrogardiographic changes due to mutations in sodium channels of the heart (SCN5A) and increased risk of sudden cardiac death.
The patient fully recovered. An implantable defibrillator was implanted to treat eventual further cardiac arrhythmias before discharge. The patient was referred for genetic linkage analysis. In the future, total thyroidectomy will be performed.
Conclusion: Thyroid storm is a rare, but treatable, potential fatal emergency. In rare cases, ventricular fibrillation is the presenting symptom of a thyroid storm. In our case, the presence of Brugada syndrome probably predisposed to the near-fatal ventricular arrhythmia.